Change-speed gear



March 4, 1930. A. J. ROWLEDGE 1,749,264

CHANGE SPEED GEAR Filed Dec. 3, 1924 5 Sheets-Sheet 1 61 Hanna ,4

March 4, 1930. A. J. ROWLEDGE 4 1,749,264

I CHANGE SPEED GEAR Filed Dec. 5, 1924 5 Sheets-Sheet 2- jxfiarcl 1T owlezfye March 4, 1930. A. J. ROWLEDGE 1,749,264

CHANGE SPEED GEAR Filed Dec. 3, 1924 3 Sheets-Sheet 3 hfx6 A CAI i V as Suvcmfqz jnlfiar elffozgled e Patented Mar. 4, 1930 y UNITED ,STATES PATENT OFFICE ARTHUR JOHN ROWLIEDGE, F DERBY, ENGLAND, ASSIGNOR '10 ROLLS-ROYCE LIMITED,

' I OF DERBY, ENGLAND GRANGE-SPEED GEAR 0 Application filed December 3,

This invention relates to change speed gear and is specially useful in aero engines having two-speed gear. The invention is a novel system of changing the gear by hydraulic force. The invention consists in a new hydraulic device in operable connection with the change speed mechanism actuated by the I scavenger oil under the influence of a force I pump with controlling means operable by the driver, the device being so arranged that the relief port of the compression system closed by the piston, except when the piston is at the end of its stroke, whereby the pump has to overcome the resistance of the mem 15 here to be moved, but is free from the neces sity of overcoming a spring loaded valve of greater resistance. Preferably there is connected to the mechanism a toggle arrangement whereby according to the position of the toggle one or the other of two plate clutches isclosed, such clutches being respec; tively'operatively connected to one and the other speed gear.

Preferably also the mechanism is connected to' the throttle valve so that except during a predetermined range of throttle openin the'operationsotthe mechanism is sus en ed. A v v s an example of this invention I may make the apparatus as follows At a suitable position in the conduit through which used oil is being pumped back,

to the supply tank (hereinafter called the return conduit) is, a two-way valve me-' chanically connected to the throttle valvein such manner that when the throttle valve. is open the oil is pumped direct to the supply tank, but when thethrottle valve is closed, or

closed to a predetermined amount, the 'oil is delivered via a conduit (hereinafter referred to as the supply conduit) to and through an oil ressure system, and thence via a conduit- (hereinafter referred to as the 'exhaust conduit) into the return conduit at a point beyond the said valve.

-nection with the exhaust conduit.

1924, Serial No. 753,692, and'i n Great Britain December 4, 19a3.

The oil pressure system consists of a presser cylinder with a piston therein and a special valve and a special arrangement of conduits as hereinafter described. The presser cylinder has four openings or ports one at each end beyond the stroke movement of the piston (hereinafter referred to as end ports) and two others respectively at such a distance from each end that when the piston makes a full stroke it asses one of such openings early in the stro e and the other shortly before completing the stroke (hereinafter referred to as inner ports).

The valve is a multiple way valve to be moved into one or the other of two positions. To it are connected the supply conduit from the return conduit, the exhaust conduit and the conduits from each of the ports of the cylinder. The valve is constructed so that in one posltion one of the end ports of the cylinder is in through connection with the suppl conduit, the adjoining inner port is closed: and the remaining two ports are in through connection-With the exhaust conduit and in the other position the converse is brought about, that is to say, the other end port of the cylinder is in through connection with the supply conduit, the adjoining inner port is closed and the othertwo are in through con- To the piston a piston rod is connected which asses out at one end through asuita-- ble pac ing gland formed in theend of the cylinder.

Thel piston' rod operates on one end of a leverwhich at the other end is connected to a spring loaded toggle and which, through the instrumentality of a suitable mechanism, causes either the one or the other of two plate clutches to be closed, thus connecting the driving mechanism to one system of gear or another. The eifect of the toggle is, firstly,

that the hydraulic device has only to reverse the toggle, that isto say push it past the critical or neutral point, and second, that either gine.

. scribed protrudes.

member shown in the one or the other of the clutches isclosed with a predetermined pressure.

In the accompanying drawings an example of my invention is illustrated.

Fig. 1 is a diagrammatical view showing the working of the device on a 12 cyinder en- Fig. 2 an enlarged view of the change s eed case showing in section on a central vertlcal plane the presser cylinder and valves on line XX of Fig. 3. Fig. 3 is a front view showing the presser cylinder and valves in section on line YY of Fig. 2 looking from left to right. Figs. 4:, 5, 6 and 7 are respectively a central vertical section of the barrel of-a multiple way. barrel valve and sections on lines RS and T of Fig. 4. a-are the cylinders, a the crank shaft case with flange a. and a is the throttle valve. 6 is the case containing the change speed mechanism with flange b secured to the crank shaft case by bolts passing through the flange a and passin through bosses b formed on the change speed case and nuts 6 6* is a facing formed on the case b to support the presser cylinder hereinafter described and b is a boss on the case through which the ais a rocking shaft the rotating of which through an arc actuates the change speed mechanism, extending. from within the casing through the boss 6 and through holes in the two seel plates hereinafter referred to, 0 is a two arm toggle lever the arms being projected from a hubc keyed to shaft 0, care two'steel plates the inner having an extension a secured to the casing 12 by stud and nut c and a. a is a flat circular formed with shouldered trunnions 0" which v are threaded at their ends. These trunnions pass through holes in the plates 0 and are mounted and rock in steel bearings 0' which are secured to the plates 0 by rivets- 0 c is a rod which at one end passes through and slides in a holein the centre of the circular member 0 and at the other end has a bifurcated end piece of pivotally hinged to an arm of thetoggle lever. 0 is the toggle spring abutting at one end against the'circular member 0 and at the other end against a perforated circular member 0 threaded on the rod 0 and resting.

on a flange on the bifurcated end piece, 0 are nuts securing the trunnions a" in their bearings, a is an annular member secured to the boss I) by bolts 0 and nuts 0, a are two annular flanged members, the main parts fitting holes through the two plates respectively, and the flanges laying against the plates and fastened thereto by rivets c". a" is a nut engaging the shaft 0 and securing the parts in position. The lines 0 show the resting pos1t1on of the toggle lever alternative to that rawings. The operation of the toggle is as follows :-'When the piston moves one arm of the toggle lever a, turning the shaft 0 in doing so, the other arm of the leading from bore d to shaft hereinafter detog le lever is moved to the osition shown by hne 0 and for the first hal of such movement pushes the rod 0. against the reaction of the spring 0 9 (the rod sliding through the hole in the member 0?) Directl the arm of the toggle lever to which the ro is attached has passed the position of alignment with such rod, the reaction of the spring forces such arm to the posltion shown by the line 0 In result the lever a must assume one or the other of the extreme positions of its range of movement. d is a presser cylinder formed with a large boss d integral therewith extending from end to end of the cylinder, (1 is a in dotted lines in Fig. 2 to which the conduit to the tank is connected. d is passage way from the bore d to the bore (1 This passage way is shown in chain dotted lines 1n Fig. 3 being in front of the section plane. The passage way starting from bore d comes upwards from the surface of the paper, bears to the left and then recedes and joins the bore (1 d is a flange formed on andintegral with the cylinder (1 and with threaded holes therein. d is the piston in the presser cylinder, (Z the piston rod attached. thereto with an enlarged cylindrical end (1 sliding in a tubular guide constituted by the member (1 hereinafter referred .to. The enlarged end has a hole or socket therein which is engaged by the ball end of the toggle lever. (1 is a tubular member having integral therewith a flange extension (2 with holes registering with the threaded holes of the flange d and secured to the cylinderby studs i and nuts d". d? is an internal flange also integral with the tubular member d, with a cylindrical extension formed thereon (1 forming astufling box, (1 is packing material. d is a cap internally threaded to engage external threads on' the cylindrical ex tension (1 (by the screwing of which the packing can becompressed as required) with a central hole for the rod to pass through and with external axial serrations, d" is an annular member internally serrated engaging the serrations on and forming a locking late for, the cap (1 located and secured y a flange d, which is held between the flanges of the cylinder and the tubular member. e is a barrel valve in the bore (1, e the s indle actuating it under the control of the 'ver. One end of the barrel is open. There is a 90 inclined bore opening into the bore d shown and f the spindle actuating same. The bar rel is open at one end and has a gap in its circumferential wall which registers with the orifice of the conduit (1 or of the bye-pass conduit d according to the position of the valve. The spindle f is mechanically conhected to, and is automatically actuated by, the throttle mechanism so that the gap opening is registered with the bye-pass when the opening of the throtte valve is above a predetermined limit and with the conduit d when below that limit. 9 is the oil pump returning theloil from the engine sump to the tank 9 g is a conduit from the pump (1 connected to the end of the bore (1, g is a conduit leading from the open end of the bore d to the tank and 9 shown in dotted lines (Fi 2) is a continuation of the bye-pass conduit (1 connecting with the conduit g.

The effect of the described apparatus is that .when the throttle is opened to a predetermined amount the oil passes direct to the tank via the return conduit constituted by pipe 9, bore d, valve f, passage (1", passage 9, bore d, and pipe 9 but when the throttle opening is less than the said predetermined amount the oil passes by the return conduit to the barrel 7, suppy conduit or passa e d, the side e of the barrel valve e, thence %dependcut on the position of barrel valve 0) by either the conduit (i or the conduit (1", the presser cylinder, and either the conduit d or the conduit d, the side e of barrel valve 0, exhaust conduit or bore d and the return conduit.

' at is claimed is 1. An engine controlled by a throttle valve and including a shaft rotatable from either of two different predetermined positions to the other, operating means connected to said 3 shaft, a spring toggle mechanism connected to said operating means and normally tending to hold the shaft in one or the other of its said positions, a servo-motor operably connected to said toggle mechanism, and means controlling the operation of said throttle valve and servo-motor.

link to maintain said lever in a predetermined operative position, mechanism engaging the other arm of said lever to move in opposite directions against the resistance of said yielding means, a throttle valve controlhng the operation of said engine, manually operable means controlling the operation of said mechanism, and means controlled by the throttle valve during a predetermined range of throttle opening to suspend the operation of said mechanism.

In witness whereof l have signed this specification. 

